Xx Advantages of Experience Concerning HARDTACK, Mr, Philip R. Moore, of Los Alamos, later explained why the B-57D aircraft was capable of obtaining samples safely which could not be gathered by other aircraft: "It would be possible to get a sample from the stem of the cloud with a Piper Cub but you would soon have a dead pilot." Drawing a chalk chart on the blackboard of his office, Mr, Moore illustrated, * A B-57B for instance,, would have to fly some 100 miles under the mshroom umbrella of the nuclear cloud to get to the only part it could sample--the stem, During that 100 miles, the pilot and plane would be receiving great quantities of ‘shine! (radiation). The plane and crew would receive a duplicate dosage on the way back from under the cloud, A B-57D would be able to climb to the edge of the mshroom cloud, penetrate it for the sampling mission, bank and dive from the cloud upon completion of the mission and pick up only that radiation he started getting when he penetrated."“- But despite the availability of the B-57D, the Test Aircraft Unit was hard pressed to obtain sufficient pilots and observers to complete the series, Mr. Paul W. Guthals, also from Los Alamos, explained the situation: Early planning for HARDTACK called for 12 shots. By the time the series started, plans called for 2h shots. .Before the series ended, a total of 33 shots were fired, besides the two in NEWREEL, It was our biggest test 191 SWEH-2-003h, (0 og